Exploring synergies and opportunities at the interface between culture, ritual and science for landslide risk reduction

Abstract

Landslides cause substantial human and economic losses globally, notably in lower and middle-income mountainous countries such as Nepal. However, efforts to reduce landslide risks lag behind those for other hazards, with very few successful examples of knowledge integration in landslide risk reduction. This ethnographic study, informed by political ecology and cultural discourses, aims to understand the impacts, risks and vulnerabilities of landslides faced by historically marginalized ‘Tamang’ people in Nepal’s Sindhupalchok district, the district hardest hit by the 2015 Gorkha earthquake. The study unveils continually evolving local strategies for reducing the risks of frequent small-to-medium scale landslides that are most common and worrying for local people but are often overlooked by ‘outsiders’ due to their perceived lesser impacts.
My research highlights that people’s vulnerabilities to landslides are rooted in systemic marginalization and resource extraction. Even small-to-medium scale landslides cause significant cumulative impacts as compared to larger events. Local inhabitants use diverse and sophisticated knowledges and tactics for reducing landslide risks and impacts. However, such knowledges are dwindling due to continued disregard from decision-makers, outmigration, and the increasing detachment from agriculture-based livelihoods, aggravated by frequent landslides and wildlife incursions on crops.
This study aims to fill key knowledge gaps regarding landslide monitoring and risk reduction. These gaps include the uncertainties inherent in landslide monitoring efforts, often based on rainfall data alone. Additionally, there exists a lack of adequate understanding around the initiation and evolution of landslides originating from less conspicuous areas as well as disparities in how rainfall, sub-surface conditions and slope deformations are perceived. To address these, I use an interdisciplinary approach, combining community observations with instrumental data on rainfall, soil moisture and acoustic emissions signals generated by slope deformation. Findings show the distinct increase in slope deformation during the summer monsoon, signalling the pivotal role of rainfall and progressive infiltration in causing slope instability. This study further demonstrates the use of cost-effective soil moisture and acoustic emission sensors, alongside rainfall, as used in this study, offer potential for continuous monitoring of vulnerable slopes at high temporal resolution, thereby enhancing the reliability of monitoring systems and bridging knowledge disparities pertinent in the field.